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1. 06:08 AM - 601 XL overheating (E.T.Gmerek)
2. 08:09 PM - Re: 601 XL overheating (Don Morrisey)
3. 09:21 PM - Re: 601 XL overheating (T. Graziano)
Message 1
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| Subject: | 601 XL overheating |
Do not archive.
I=92ve read the recent messages regarding the Jabiru 3300 engine in
other
than a Jabiru. I have been unable to achieve CHTs within Jabiru=92s
guidelines. Many thanks to the people that gave me the benefit of their
own experiences with a special thank you to Jeff Small who worked with
us for several months trying to help. Just for the record, my
configuration is an original(older, mechanical lifters/less cooling
fins) engine with a Sensenich Carbon Fiber ground adjustable prop and
the latest Jabiru 601 cowling, and a Grand Rapids EIS. The engine has
about 56 hours on it at this point, the carburetor was replaced with an
NOS pre-economizer change carb to be sure the engine was not running
lean, all probes have been checked and rechecked, air leaks in the
intake system have been eliminated (there were none), compression checks
made (hot and cold, automotive and aircraft), valves adjusted every five
hours, a =91lip=92 of about 1 =BD to 2 inches has been added to the
bottom of
the cowl at the air exit to give a greater differential, cowling sealed,
baffling =91tweaked=92 repeatedly adding =91fingerlets=92, speed bumps,
an
additional vertical baffling =91extension=92 at the #6 cylinder,
pictures
taken of the entire engine compartment as well as very detailed ones of
the baffling. These were reviewed by the Jabiru dealer on the West Coast
and nothing wrong was seen. I=92m sure there have been other things
done,
I=92m just trying to demonstrate that we have tried just about
everything
possible, without success. The latest numbers at the end of this post
indicate we still have a very large problem.
I=92d like to ask if anyone has attempted to install baffling which
would
be more the conventional Continental/Lycoming style, i.e. baffling that
directs the ram air over the bottom of the cylinders, not just the top.
The Sonex has a system for the 3300 that does just this, and, with some
alterations, would fit beneath the cowling of a 601. Obviously the steep
slope of the Sonex cowl would call for some change of the baffling, but
I called the Sonex site and had the measurements taken directly off
their demo and there would not be a very great change to their existing
=91baffle box=92. My feeling is that there is inadequate cooling air
with
the 601/Jabiru cowl and the =91full upper/lower=92 cylinder baffling
would
make better, more complete use of what is available. The cost is not
excessive, $250 plus shipping, and I=92m at the end of my rope. My next
step is to replace my Jabiru engine with a Corvair. They don=92t have
overheating problems as the full cylinder heads (3 cylinders per)
distribute/dissipate heat more efficiently/evenly. The individual I
bought the plane from sold it at 26 hours because he could not solve the
problem. He was wiser than I.
Thoughts/comments appreciated.
The latest flight test runs follow:
FLIGHT 9-10-2007
---------------------------------
INITIAL CLIMB OUT
283 299 298
351 274 323
---------------------------------
CRUISE 3000rpm 110mph indicated
295 321 331
324 274 303
---------------------------------
CRUISE 2900rpm 110mph indicated
270 291 320
303 269 292
---------------------------------
CRUISE 2800rpm 105mph indicated
271 282 312
299 266 291
---------------------------------
TOP SPEED RUN
3300rpm 120mph indicated
oil temp set off alarm at 246
---------------------------------
these next numbers are in unknown
configuration but occured after
the top speed run
301 314 333
326 262 270
---------------------------------
another 2800rpm CRUISE
269 281 304
299 271 298
oil temp 218
---------------------------------
500fpm climb at 2800rpm 95mph ind
217 oil temp
277 285 316
308 280 307
updated a little later
284 296 328
326 294 322
9/19/2007 3:59 PM
Message 2
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| Subject: | 601 XL overheating |
JP, go to the yahoo groups jabiru engine email list and sign up. Then do a
search for "Fisher Dakotahawk". A recent post from a builder in New Zeala
nd did exactly what you are thinking...built the standard lyc/conti air box
and got excellent results after everything else he tried failed. Another
builder on the list has photos in the photo section of a crossover tube he
put between the fiberglass airboxes which helped his problem. It seems to
me the standard air box accomplishes both. You could use the vertical piec
es of the Sonex air box and rivet on extensions to come up to the top of yo
ur cowl and basically create the lyc/conti style box. I plan to install my
new engine (ser # 1390) this winter with the fiberglass ducts as provided
but if that doesn't work I will quickly switch to what I just described. G
ood luck.
Don...www.donsbushcaddy.comDon Morrisey's Skunkworks
From: jptook@jptook.cnc.netTo: jabiruengine-list@matronics.comSubject: Jabi
ruEngine-List: 601 XL overheatingDate: Thu, 20 Sep 2007 06:07:27 -0700
Do not archive.
I=92ve read the recent messages regarding the Jabiru 3300 engine in other t
han a Jabiru. I have been unable to achieve CHTs within Jabiru=92s guidelin
es. Many thanks to the people that gave me the benefit of their own experie
nces with a special thank you to Jeff Small who worked with us for several
months trying to help. Just for the record, my configuration is an original
(older, mechanical lifters/less cooling fins) engine with a Sensenich Carbo
n Fiber ground adjustable prop and the latest Jabiru 601 cowling, and a Gra
nd Rapids EIS. The engine has about 56 hours on it at this point, the carbu
retor was replaced with an NOS pre-economizer change carb to be sure the en
gine was not running lean, all probes have been checked and rechecked, air
leaks in the intake system have been eliminated (there were none), compress
ion checks made (hot and cold, automotive and aircraft), valves adjusted ev
ery five hours, a =91lip=92 of about 1 =BD to 2 inches has been added to t
he bottom of the cowl at the air exit to give a greater differential, cowli
ng sealed, baffling =91tweaked=92 repeatedly adding =91fingerlets=92, speed
bumps, an additional vertical baffling =91extension=92 at the #6 cylinder,
pictures taken of the entire engine compartment as well as very detailed o
nes of the baffling. These were reviewed by the Jabiru dealer on the West C
oast and nothing wrong was seen. I=92m sure there have been other things do
ne, I=92m just trying to demonstrate that we have tried just about everythi
ng possible, without success. The latest numbers at the end of this post in
dicate we still have a very large problem.
I=92d like to ask if anyone has attempted to install baffling which would b
e more the conventional Continental/Lycoming style, i.e. baffling that dire
cts the ram air over the bottom of the cylinders, not just the top. The Son
ex has a system for the 3300 that does just this, and, with some alteration
s, would fit beneath the cowling of a 601. Obviously the steep slope of the
Sonex cowl would call for some change of the baffling, but I called the So
nex site and had the measurements taken directly off their demo and there w
ould not be a very great change to their existing =91baffle box=92. My feel
ing is that there is inadequate cooling air with the 601/Jabiru cowl and th
e =91full upper/lower=92 cylinder baffling would make better, more complete
use of what is available. The cost is not excessive, $250 plus shipping, a
nd I=92m at the end of my rope. My next step is to replace my Jabiru engine
with a Corvair. They don=92t have overheating problems as the full cylinde
r heads (3 cylinders per) distribute/dissipate heat more efficiently/evenly
. The individual I bought the plane from sold it at 26 hours because he cou
ld not solve the problem. He was wiser than I.
Thoughts/comments appreciated.
The latest flight test runs follow:
FLIGHT 9-10-2007---------------------------------INITIAL CLIMB OUT283 299
298351 274 323---------------------------------CRUISE 3000rpm 110mph ind
icated295 321 331324 274 303---------------------------------CRUISE 290
0rpm 110mph indicated270 291 320303 269 292----------------------------
-----CRUISE 2800rpm 105mph indicated271 282 312299 266 291-------------
--------------------TOP SPEED RUN 3300rpm 120mph indicatedoil temp set off
alarm at 246---------------------------------these next numbers are in unkn
own configuration but occured after the top speed run301 314 333326 262
270---------------------------------another 2800rpm CRUISE269 281 304299
271 298oil temp 218---------------------------------500fpm climb at 2800
rpm 95mph ind217 oil temp277 285 316308 280 307updated a little later28
4 296 328326 294 322
9/19/2007 3:59 PM
_________________________________________________________________
Gear up for Halo=AE 3 with free downloads and an exclusive offer. It=92s ou
r way of saying thanks for using Windows Live=99.
http://gethalo3gear.com?ocid=SeptemberWLHalo3_WLHMTxt_2
Message 3
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| Subject: | Re: 601 XL overheating |
Instead of the "air dam" for the oil cooler, I used rubber engine
baffeling type material to seal off most of the gaps around the oil
cooler to cowling so that air mostly passes through the oil cooler and
not around it.
Also, of course as mentioned here many times, I only fill my oil to a
max of about 40% on the dip stick. In hot weather, in the 90+F area, I
still can not go high power low airspeed for long without going red line
on CHT (always my #2, the left hand fwd cylinder.)
I also have deflectors in the ducts for my #4 and #3 cylinders, about
3/4 inch by 4 inches and bigger deflectors for the #5 and #6.
Do not close off the rear area where the duct ends around the #6 and #5
cylinder.
Also, see below from my archives for anything that may help. Note: this
was with the original economy mod, before the amendment to lower the
EGTs
Tony Graziano
601XL/Jab3300; N493TG, 291 hours
Submitted By:
charles.long@gm.com
Email List:
Zenith-List
Name:
Charles F. Long
Date:
Oct 23 2005
Subject:
Cooling improvements on the Zenith 601HDS w/Jabiru 3300
Description:
During my first few hours of flight, I experienced elevated
cylinder head temperatures on my Zenith 601HDS with Jabiru 3300A engine.
Also had issues with Exhaust Gas Temperature imbalance at full throttle.
The following is a summary of changes made to improve the situation.
This really just builds on the recommendations of Jabiru and Zenith to
provide plenty of cooling for the 6 cylinder engine. I would like to
thank Jeff Small, Fred Hulen, Stan Challgren as well as Pete Krotje at
US Jabiru and Andy Sylvester at Sun Coast for their contributions. As a
place to start, US Jabiru provides some good cooling suggestions at
their website:
My aircraft has the following modifications:
1) Fuel Economy Carb Kit as supplied by Jabiru.
2) Gull wing baffles between cylinders as recommended by Jabiru
3) Full deflectors angled down between the spark plugs of cylinder
#5 & #6 as recommended by Jabiru.
4) Smaller deflectors angled down between the spark plugs of #3 &
#4. These middle cylinder deflectors usually need some tuning. Would
suggest starting with 3/4" tall. On #3, I stayed at 3/4", on #4 ended up
trimming down to 1/2".
5) The inlet to the ram air ducts has a gap between the duct and
the cylinders at the bottom. This allows air to escape downward without
doing any useful work. I added some .025" aluminum plates that butt up
against cylinder's #1 & #2 to prevent this from happening. To reduce the
over cooling of the front two cylinders and force more air upward to the
rear cylinders, I angled the material upward about an 2-3=A1=A8. The
exact height needs to be determined by trial end error. The new XL cowl
has openings that are quite small and located high on the cylinders. My
modification attempts to duplicate the XL cowl openings and seems to
work quite well. At the onset, this change appears to be
counter-intuitive. Just keep it mind, the goal is to get as much use out
of every air molecule as possible!
6) Small baffles mounted between valve tappet covers. This
prevents more air from escaping without doing any useful work.
7) There is a temptation to add an L angle to the bottom rear of
each ram duct. I tried this change and it elevated my temps rather than
reducing them.
8) The oil cooler inlet is keep quite small to allow more air to
find it's way through the cylinders. I ended up with about a 1.75" x
4.00" opening. The Jabiru website provides a good discussion on this. I
tried a much bigger opening as can be seen in the picture and it
provided very little benefit.
9) Don't forget to keep your oil level midway between the Full and
Add mark. Jabiru indicates that overfilling can cause high oil temps.
My #1 cylinder was running much cooler than the #2 cylinder with
identical intake openings. I rotated the bottom of the carb 5-10 degrees
towards #1 and that took care of it. The main jet feeds the carb at the
bottom so if the carb is tilted, it can direct more fuel towards one
bank of cylinders than the other.
At full throttle, EGT's from left to right bank were 150 F
different. I suspected that air entering the carb through the 90 degree
intake elbow was piling up on the outside of the curve. I installed a
vertical divider in the elbow to keep left side air separated from the
right side air. This worked beautifully. My EGT's are now balanced
within roughly 50 F at all throttle settings including WOT. The divider
was fabricated out of a piece of 6061T6 aluminum - 5.25" x 3" x .016".
The upper and lower edges were rolled around a 1/16" cable to add
stiffness and prevent cutting of the rubber elbow. Finished height is
just slightly over 2.25 inches so it fits snuggly within the elbow.
After rolling the edges, the part was bent 90 degrees to fit the elbow
contour by wrapping around a 2" diameter plastic pipe. After it springs
back, you end up with a 2" bend radius whichis equivalent to the center
radius of the elbow. Once the part is finished, the cable can be removed
(prevents a potential corrosion issue). The rubber elbow is quite
pliable in the free state, so the flow divider installs quite easily.
After installation, the divider is trapped pretty well in all
directions.
With the Aid of my Engine Information System from Grand Rapids
Technology, I was able to monitor my progress for each Cylinder Head
Temperature: I now have the following readings at 60 F ambient
temperature (my engine has 28 hours TT, so temps have fallen after
break-in):
--------------------------------------------------------------------
RPM IAS CHT1 CHT2 CHT3 CHT4 CHT5 CHT6 EGT5 EGT6
--------------------------------------------------------------------
2600 110 247 228 259 247 272 245 1465 1423
2700 120 242 221 253 239 265 240 1486 1451
2800 125 242 226 252 242 265 244 1512 1498
2900 130 253 246 260 260 268 262 1482 1538
WOT 138 288 293 293 298 301 297 1463 1482
--------------------------------------------------------------------
This was a quickie test and temps/speeds were not totally
stabilized. Oil temps varied from 200-230F depending on Throttle
setting. This is an area where a NACA inlet could improve Oil Cooler
efficiency. The new XL cowl incorporates one of these. The Flight Test
was run at 3500 ft MSL and an ambient of 60F. Wheel pants and gear
fairings are installed with an otherwise stock airframe.
The Jabiru is running very nice. I'm happy with the installation,
power and smoothness after getting through these initial teething
problems. Fuel burn at lower cruise settings is estimated at a miserly 4
gph. With the fat wing, I suspect fuel burn will go way up at the higher
cruise speeds.
Chuck Long
Zodiac 601HDS
N601LE, 28 hr TT
-------------------------
Subject: Subject: 601 XL overheating
From: E.T.Gmerek (jptook@jptook.cnc.net)
Date: Thu Sep 20 - 6:08 AM
Do not archive.
I=92ve read the recent messages regarding the Jabiru 3300 engine in
other
than a Jabiru. I have been unable to achieve CHTs within Jabiru=92s
guidelines. Many thanks to the people that gave me the benefit of their
own experiences with a special thank you to Jeff Small who worked with
us for several months trying to help. Just for the record, my
configuration is an original(older, mechanical lifters/less cooling
fins) engine with a Sensenich Carbon Fiber ground adjustable prop and
the latest Jabiru 601 cowling, and a Grand Rapids EIS. The engine has
about 56 hours on it at this point, the carburetor was replaced with an
NOS pre-economizer change carb to be sure the engine was not running
lean, all probes have been checked and rechecked, air leaks in the
intake system have been eliminated (there were none), compression checks
made (hot and cold, automotive and aircraft), valves adjusted every five
hours, a =91lip=92 of about 1 =BD to 2 inches has been added to
the
bottom of
the cowl at the air exit to give a greater differential, cowling sealed,
baffling =91tweaked=92 repeatedly adding =91fingerlets=92, speed
bumps,
an
additional vertical baffling =91extension=92 at the #6 cylinder,
pictures
taken of the entire engine compartment as well as very detailed ones of
the baffling. These were reviewed by the Jabiru dealer on the West Coast
and nothing wrong was seen. I=92m sure there have been other things
done,
I=92m just trying to demonstrate that we have tried just about
everything
possible, without success. The latest numbers at the end of this post
indicate we still have a very large problem.
I=92d like to ask if anyone has attempted to install baffling which
would
be more the conventional Continental/Lycoming style, i.e. baffling that
directs the ram air over the bottom of the cylinders, not just the top.
The Sonex has a system for the 3300 that does just this, and, with some
alterations, would fit beneath the cowling of a 601. Obviously the steep
slope of the Sonex cowl would call for some change of the baffling, but
I called the Sonex site and had the measurements taken directly off
their demo and there would not be a very great change to their existing
=91baffle box=92. My feeling is that there is inadequate cooling air
with
the 601/Jabiru cowl and the =91full upper/lower=92 cylinder baffling
would
make better, more complete use of what is available. The cost is not
excessive, $250 plus shipping, and I=92m at the end of my rope. My
next
step is to replace my Jabiru engine with a Corvair. They don=92t have
overheating problems as the full cylinder heads (3 cylinders per)
distribute/dissipate heat more efficiently/evenly. The individual I
bought the plane from sold it at 26 hours because he could not solve the
problem. He was wiser than I.
Thoughts/comments appreciated.
From: E.T.Gmerek (jptook@jptook.cnc.net)
Date: Thu Sep 20 - 6:08 AM
Do not archive.
I=92ve read the recent messages regarding the Jabiru 3300 engine in
other
than a Jabiru. I have been unable to achieve CHTs within Jabiru=92s
guidelines. Many thanks to the people that gave me the benefit of their
own experiences with a special thank you to Jeff Small who worked with
us for several months trying to help. Just for the record, my
configuration is an original(older, mechanical lifters/less cooling
fins) engine with a Sensenich Carbon Fiber ground adjustable prop and
the latest Jabiru 601 cowling, and a Grand Rapids EIS. The engine has
about 56 hours on it at this point, the carburetor was replaced with an
NOS pre-economizer change carb to be sure the engine was not running
lean, all probes have been checked and rechecked, air leaks in the
intake system have been eliminated (there were none), compression checks
made (hot and cold, automotive and aircraft), valves adjusted every five
hours, a =91lip=92 of about 1 =BD to 2 inches has been added to
the
bottom of
the cowl at the air exit to give a greater differential, cowling sealed,
baffling =91tweaked=92 repeatedly adding =91fingerlets=92, speed
bumps,
an
additional vertical baffling =91extension=92 at the #6 cylinder,
pictures
taken of the entire engine compartment as well as very detailed ones of
the baffling. These were reviewed by the Jabiru dealer on the West Coast
and nothing wrong was seen. I=92m sure there have been other things
done,
I=92m just trying to demonstrate that we have tried just about
everything
possible, without success. The latest numbers at the end of this post
indicate we still have a very large problem.
I=92d like to ask if anyone has attempted to install baffling which
would
be more the conventional Continental/Lycoming style, i.e. baffling that
directs the ram air over the bottom of the cylinders, not just the top.
The Sonex has a system for the 3300 that does just this, and, with some
alterations, would fit beneath the cowling of a 601. Obviously the steep
slope of the Sonex cowl would call for some change of the baffling, but
I called the Sonex site and had the measurements taken directly off
their demo and there would not be a very great change to their existing
=91baffle box=92. My feeling is that there is inadequate cooling air
with
the 601/Jabiru cowl and the =91full upper/lower=92 cylinder baffling
would
make better, more complete use of what is available. The cost is not
excessive, $250 plus shipping, and I=92m at the end of my rope. My
next
step is to replace my Jabiru engine with a Corvair. They don=92t have
overheating problems as the full cylinder heads (3 cylinders per)
distribute/dissipate heat more efficiently/evenly. The individual I
bought the plane from sold it at 26 hours because he could not solve the
problem. He was wiser than I.
Thoughts/comments appreciated.
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